The onset of hypothermia is a serious risk to the health of any person stranded in a cold environment. In severe cases amputation of limbs or death can result. Hypothermia can also be an added complication to those suffering injuries arising from an aircraft emergency landing, auto or snowmobile accident, or the like, decreasing the chances of survival for the injured as well as those who may be initially well enough to treat the injured. Typically when a person is stranded, or when there are survivors of an accident in a cold region, shelters and equipment for providing heating, food and first aid are improvised from the surrounding natural environment and/or a failed vehicle or wreckage. Understandably, such equipment and shelter are often inadequate, and in many circumstances may in fact be impossible to provide due to physical impairment from injuries, or lack of suitable materials for improvisation, or the severity of cold temperatures. Even if there are conventional portable shelters available, eg. tents, such are not well adapted to meet the needs of stranded and/or injured persons in cold: manual dexterity, particularly of the hands, is required for manipulation of parts during erection of conventional tents, which dexterity is normally impaired in severe cold; and there are few, if any, design elements in conventional tents for heat preservation or generation, or which facilitate use by severely injured persons under the assistance of others.
In order to provide insulation from cold ground, some prior tent designs have incorporated an inflatable floor, eg. Canadian Patent No.1,126,612 (Westrop). Another has provided for an inflatable floor and walls combination, ie. Canadian Patent No. 1,181,655 (Topolnikov). But these do not disclose features which facilitate the shelter of, or access to shelter by, severely injured persons who must be carried into the shelter by one or more assistants. Also, they do not incorporate features for heat preservation.
Canadian Patent No. 1,262,856 (Hayashida) discloses a tent for emergency use in extreme cold conditions, but such is not easy to set up, particularly for one suffering from injuries or cold impairment. Also, notwithstanding a hinged front opening for better access to the interior by an injured person, such opening does not allow for complete, unobstructed access to the entire floor area which, for example, would be advantageous when one (or more) assistant is carrying an injured person into the tent and therefore requires sufficient room to manoeuvre the injured person onto the interior floor without putting the assistant at additional risk of injury, eg. by straining to fit through an opening while carrying the injured person. Furthermore, there is no feature of the Hayashida tent to limit heat loss upon entry or exit from the tent. None of the foregoing patents contemplates an emergency survival kit in which the tent is one part.
It is apparent that there is a need for an emergency shelter for extreme cold conditions that is easy to set-up in severe cold, provides easy access for a severely injured (immobilized) person under assistance, and provides features favouring heat retention and limited heat loss when a person, other than an immobilized person, enters or exits the shelter. Furthermore, there is a need for such a shelter which additionally facilitates heat generation, provides physical comfort for the occupants, and facilitates rescuers in locating the persons using the shelter. It is therefore an object of the present invention to meet the foregoing needs.